Rightmark's Audio Analyzer was used to estimate several characteristics of
the HDAV1.3, including signal-to-noise ratio (SNR), total harmonic distortion
(THD), intermodulation distortion (IMD), and stereo crosstalk. Tests were performed
at sample rates of 44.1, 48, 96, and 192 kHz and bit depths of 16, 24, and 32
(int) bits. Inputs and outputs were set up exactly as per Asus'
RMAA test guide for the Xonar HDAV, in which the analogue RCA outputs were
connected to the line-in jack using an mini to RCA splitter. Line-in level was
set to 100, and speaker out level was set to 40.

Subjective Testing

A total of 10 different tracks from 8 different CDs were used to perform an
A/B listening comparison. CDs were playing in iTunes, with the application,
driver, and system sample rates all set to 44.1 kHz in Vista's sound panel to
avoid resampling. The default audio device was set to "Speakers",
which allowed the HDAV1.3 to output simultaneously via S/PDIF and analogue outputs.
Both of these outputs were fed into a Yamaha HTR-5790 A/V Receiver. All DSP
filters on the receiver were turned off by setting the audio mode to "straight".
The two sources were then volume-matched (by ear) in the Xonar sound panel.
This turned out to be unnecessary, since both sources sounded the equal at 100
volume. The speakers hooked up to this system were a pair of floor-standing
transmission-line speakers custom-built by SPCR editor Mike Chin. They sound
extremely clear, and are estimated to have a flat frequency response down to
approximately 100 Hz (if only the same could be said for the room).

Using this setup, we listened to each test track through fully using each output,
and then a third time switching back and forth between the two sources. No attempt
was made to do blind ABX testing. This setup allowed us to compare the DACs
and op-amps in the HDAV1.3 against the same circuitry in the receiver. All other
elements of the signal chain remained constant between the two tests.

Autumn, Pt. 3: My favorite rendition of Vivaldi's classic composition.
This track features a large dynamic range in solo violin and full orchestra.

Estimating DC Power

The following power efficiency figures were obtained for the
Antec Earth Watts
power supply used in our test system. Note that the results are for the 430,
while our test system for the HDAV1.3 used the 380W model. It is likely that
the 380W model has slightly higher efficiency in the range we are using it,
but the difference is unlikely to be significant.

Antec Earth Watts 430 TEST RESULTS

DC Output (W)

42.7

65.9

92.5

150.6

AC Input (W)

60

87

118

186

Efficiency

70.8%

75.6%

78.3%

81.0%

This data is enough to give us a very good estimate of DC demand in our
test system. We extrapolate the DC power output from the measured AC power
input based on this data. We won't go through the math; it's easy enough
to figure out for yourself if you really want to.